In computer graphics, illuminating a scene is a complex task, typically consisting of cycles of adjusting and rendering the scene to see the e ects. We propose a technique for visualization of light as a tensor eld via extracting its properties (i.e. intensity, direction, di useness) from radiance measurements and showing these properties as a grid of shapes over a volume of a scene. Presented in the viewport, our visualizations give an understanding of the illumination conditions in the measured volume for both the local values and the global variations of light properties. Additionally, they allow quick inferences of the resulting visual appearance of (objects in) scenes without the need to render them. In our evaluation, observers performed at least as well using visualizations as using renderings when they were comparing illumination between parts of a scene and inferring the nal appearance of objects in the measured volume. Therefore, the proposed visualizations are expected to help lighting professionals by providing perceptually relevant information about the light in a scene.